Add Job Service Dashboard Schedules testcase

[YangJiao0817]

Fix #17949

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Comprehensive Summary of your change

Issue being fixed

Fixes #(issue)

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[codecov]

Codecov Report

Merging #18555 (2064d9d) into main (8df99a5) will decrease coverage by 0.05%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #18555      +/-   ##
==========================================
- Coverage   67.41%   67.36%   -0.05%     
==========================================
  Files         984      984              
  Lines      107010   107010              
  Branches     2670     2670              
==========================================
- Hits        72136    72092      -44     
- Misses      30993    31038      +45     
+ Partials     3881     3880       -1     

Flag	Coverage Δ
unittests	67.36% <ø> (-0.05%)	⬇️

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see 7 files with indirect coverage changes